In crimping heads of this kind, used in particular for crimping food cans of non-circular outline ("shaped cans"), the guide wheel associated with each crimping roller is held in contact with the cam surface by a spring. Although operation with return springs is satisfactory so long as the crimping head is working at a low rate, the same is not true when the rate is significantly increased. Inertia effects then become important and cause the guide wheels to lift off undesirably. In addition, since the springs are subjected to violent forces at a high frequency, they need to be replaced periodically.